A Case of Type 1 Diabetes Mellitus with Klinefelter’s Syndrome

Type 1 diabetes mellitus (T1DM) is a model of chronic autoimmune disease beginning with genetic susceptibility in affected individuals and progressing to autoimmune destruction of β cells, precipitated by environmental insult. Many of the patients with T1DM have associated genetic disorders such as Klinefelter’s syndrome (KS), Turner’s syndrome, Down’s syndrome, and Noonan’s syndrome. This paper reports a case of 15-year-old boy diagnosed with T1DM accompanying KS, 47,XXY karyotype. A 14-year-old adolescent was admitted to The Hospital of Başkent University Faculty of Medicine for weight loss, polyuria, and polydipsia. He presented for evaluation of diabetic ketoacidosis. His fasting blood glucose (301 mg/dL) was markedly elevated, pH (7.32) and HCO3 (10 mEq/L) levels were slightly low, and serum ketone test was positive due to ketoacidosis. The patient was born to a 27-year-old mother and was the first child of non-consanguineous parents. His sister was healthy, without remarkable medical history. There was no family history of diabetes or chromosomal abnormality, but his father and uncle suffered from rheumatoid arthritis. There are many studies that denote a dramatically increased risk of T2DM in KS. There are a few reports on KS accompanying T1DM. The present patient with T1DM was diagnosed as KS during his follow-up. Although he was at puberty on onset, on consecutive examination, we observed delay in puberty, such as lack of both secondary sexual characters and testicular volume increase. For differential diagnosis, chromosome analysis was performed. The result was 47,XXY karyotype, thus the diagnosis of KS was established. In conclusion, based on the findings presented in recent reports, KS should be considered in male patients with delayed puberty especially in the ones diagnosed with T1DM.